Factors influencing the stability of freeze-dried stress-resilient and stress-sensitive strains of bifidobacteria
Factors influencing the stability of freeze-dried stress-resilient and stress-sensitive strains of bifidobacteria
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DOI：
10.3168/jds.2012-6327
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发表时间：
2013-06-01
影响因子：
3.5
通讯作者：
O'Sullivan, D. J.
中科院分区：
文献类型：
--
作者：
Celik, O. F.;O'Sullivan, D. J.
冷冻干燥是一种常见的保存益生菌的方法，包括双歧杆菌，用于进一步的工业应用。然而，冷冻干燥双歧杆菌的稳定性取决于冷冻干燥方法和随后的储存条件。这项研究的主要目标是开发一种优化的冷冻干燥程序，并确定温度、水分活度和大气对冷冻干燥双歧杆菌存活的影响。为了达到这些目标，一种商业上使用的对压力有弹性的双歧杆菌菌株，动物双歧杆菌SSP。使用了乳酸杆菌BB-12和对压力条件更敏感的特征肠道菌株长双歧杆菌DJO10A。研究了以海藻糖为保护剂的冷冻干燥方法，该方法在冷冻干燥过程中几乎不会造成冻干过程中的活力损失。当使用这种冷冻保护剂时，复苏介质、温度和时间对回收率没有显著影响。研究了温度(-80~45℃)、水分活度(0.02~0.92)和气氛(空气、真空和氮气)对冻干粉在储存过程中稳定性的影响。冻干动物假单胞菌。乳酸杆菌BB-12在所有测试条件下都能存活，其中最适存活温度为21摄氏度，水活度为0.44，并测试了所有3种大气。肠道适应菌株B.long um，DJO10A对不同的贮藏条件更为敏感，但在最佳条件下仍能保持较好的稳定性。这些最佳贮藏条件包括冷冻贮藏、以氮代氧、水分活度在0.11~0.22之间。这些结果表明，需要优化的储存环境来维持应激敏感双歧杆菌菌株的生存能力，而具有应激弹性的双歧杆菌菌株可以在广泛的储存条件下保持生存能力，这在那些可能无法随时获得受控冷藏条件的国家是可行的。
Freeze-drying is a common method for preservation of probiotics, including bifidobacteria, for further industrial applications. However, the stability of freeze-dried bifidobacteria varies depending on the freeze-drying method and subsequent storage conditions. The primary goals of this study were to develop an optimized freeze-drying procedure and to determine the effects of temperature, water activity, and atmosphere on survival of freeze-dried bifidobacteria. To address these goals, a commercially used bifidobacteria strain that is resilient to stress, Bifidobacterium animalis ssp. lactis Bb-12, and a characterized intestinal strain that is more sensitive to stress conditions, Bifidobacterium longum, DJO10A, were used. A freeze-drying protocol was developed using trehalose as the cryoprotectant, which resulted in almost no loss of viability during freeze-drying. Resuscitation medium, temperature, and time did not significantly influence recovery rates when this cryoprotectant was used. The effects of temperature (-80 to 45 degrees C), water activity (0.02 to 0.92), and atmosphere (air, vacuum, and nitrogen) were evaluated for the stability of the freeze-dried powders during storage. Freeze-dried B. animalis ssp. lactis Bb-12 was found to survive under all conditions tested, with optimum survival at temperatures up to 21 degrees C, water activities up to 0.44, and all 3 atmospheres tested. The intestinal-adapted strain B. longum, DJO10A was much more sensitive to the different storage conditions, but could be adequately maintained using optimum conditions. These optimum storage conditions included frozen storage, replacement of oxygen with nitrogen, and water activities between 0.11 and 0.22. These results indicated that an optimized storage environment is required to maintain viability of stress-sensitive bifidobacteria strains, whereas stress-resilient bifidobacteria strains can maintain viability over a wide range of storage conditions, which is practical in countries where controlled cold storage conditions may not be readily available.